1. Field of the Invention
The present invention relates to a digital binaural hearing aid employing a digital signal processing chip programmed in part utilizing an erasable programmable read only memory (EPROM) provided in the hearing aid.
2. Brief Statement of the Prior Art
The need to improve the hearing of an individual has been looked upon as a worthwhile goal for many years. The first "hearing aids" merely consisted of an individual cupping his or her hand behind their ear or utilizing an ear trumpet to focus audio waves onto the person's ear drum. These rudimentary hearing aids were replaced by heating aids which merely electrically amplified the audio waves.
Although these types of "amplified" heating aids did improve the user's hearing to some degree, it was determined that the user's inability to adequately hear was not just a function of the strength of the signal received by the ear, but was also a function of the inability of the user to discern spoken words in the presence of background noise. Consequently, the next stage of hearing aids employed one or more analog filters which were designed to filter out background or extraneous noise.
Additional improvements to these types of heating aids resulted in programmable devices which were implemented utilizing analog circuits and analog signal processing. Examples of these types of hearing aids are shown in U.S. Pat. Nos. 4,947,432, issued to T phlom; 4,947,433, issued to Gebert; 4,989,251, issued to Mangold; and 5,083,312, issued to Newton et al. Further improvements are described in U.S. Pat. Nos. 4,731,850 and 4,879,749, issued to Levitt et al, and 4,887,299, issued to Cummins et al, which describes hearing aids including digital signal processing. However, none of these references describe a programmable hearing aid which would include a large number of filters provided over a relatively large frequency band.